glen campbell played the final show of his i lustrous career last night in napa, california. he is suffering from al alzheimer's. he sat down with cnn's miguel marquez. >> reporter: last year, the rhinestone cowboy made a stunning announcement. >> what they diagnose me as? >> alzheimer's. what's alzheimer's? how do you -- >> you start losing your memory. and your ability to reason. ♪ some days i'm so confused lord ♪ ♪ my past gets in my way >> reporter: this isn't glen campbell's first major challenge. he weathered career ups and down and battled drug and alcohol addiction. i was foergiven for being a dummy. >> reporter: after five decades as a musicing icon, the entertainer is taking his final bow. ♪ ghost on the canvas >> reporter: two summers ago he released his final album, "ghost on the canvas," now wrapping up his farewell tour with a backing band that it features three of his children, including daughter ashley. >> he looks at me sometimes confused and i'll just smile at him. i just try and p make him feel like he's surrounded by people that love him on stage.